1. Field of the Invention
This invention relates generally to variable displacement pumps and more particularly to a variable volumetric output adjustment means for a concentrate pump utilized in a pre-mix liquid dispensing system.
2. Description of the Prior Art
Variable displacement pumps are generally known and involve many types of configurations. Examples of such apparatus include the variable displacement pump shown and described in U.S. Pat. No. 2,327,787, issued to R. M. Heintz on Aug. 24, 1943, and the output regulating means disclosed in U.S. Pat. No. 1,475,508, issued to R. Esnault-Pelterie on Nov. 27, 1923. Also an adjustable clearance mechanism for compressors is disclosed in U.S. Pat. No. 2,047,167 issued to H.C. Heller on Jul. 7, 1936. While such apparatus is considered to operate as intended for their specific applications, such apparatus nevertheless includes inherent limitations and is generally unsuitable for use in connection with a ratio proportioning pump that mechanically provides two liquids dispensed to a mixing valve of a post-mix dispenser at exact ratios and cannot readily be added to existing ratio proportioning liquid dispensing pumps.